We can use the vertical angle theorem which states that any two opposite angles are congruent. So, you can just set the two measures equal to each other and solve for x:




So, your answer is
20°.
Answer:
`18. x=9
19. x=4
20. x=25,5
21. x=3
22. x=3,5
23. x=10
Step-by-step explanation:
Total distance = 200 miles
Time needed for the first 100 miles
= 100 ÷ 40 = 2.5 hours
Time needed for the second 100 miles
= 100 ÷ 50 = 2 hours
Total time = 2.5 + 2 = 4.5 hours
Average speed = 200 ÷ 4.5 hours = 44.4 miles per hour